The invention relates to a method for regulating a cooling device fitted in or to a switchgear cabinet, by means of a regulating device, wherein the temperature of the switchgear cabinet interior air is detected and an interior fan assigned thereto for generating an interior air flow through an evaporator and providing cooling air is switched on if the detected temperature of the switchgear cabinet interior air exceeds an upper setpoint temperature, and is switched off if the detected temperature falls below a lower setpoint temperature, and to an apparatus for performing the method.
A method of this type for regulating a cooling device fitted to a switchgear cabinet and an apparatus for performing the method are disclosed in DE 44 13 128 C2. By means of the cooling device, switchgear cabinet interior air which increases during operation of built-in components supplying dissipated heat is kept below a temperature which would be disadvantageous for the built-in components, and the dissipated heat produced within the switchgear cabinet is dissipated from the switchgear cabinet. The cooling device has several circuits which in conjunction cool the switchgear interior air. An interior air circuit is driven by an interior fan of the cooling device. A temperature sensor is located in the interior of the cooling device measuring the sucked warm switchgear cabinet interior air. A cooling circuit with a fluid coolant and an ambient air circuit are switched on or off in accordance with a predetermined set temperature. The heat energy of the switchgear cabinet interior air is absorbed by a condenser from the coolant of the cooling circuit. Then, the coolant is highly compressed by a compressor, so that it reaches a higher temperature level in a condenser than the ambient air. Thus, the heat energy transported in the coolant may be supplied to the ambient air circuit which is driven by an external fan. For regulating the interior temperature of the switchgear cabinet or the switchgear cabinet interior air, respectively, the cooling device is operated at intervals wherein the compressor and the external fan are switched on and off at intervals in response to the temperature by means of a regulating device within the apparatus. For measuring the temperature within the cooling device, the switchgear cabinet interior air is guided past a temperature sensor by means of the interior fan, wherein operation of the interior fan contributes significantly to energy consumption.
Other cooling devices for switchgear cabinets are shown in DE 10 2006 051 904 A1, DE 199 12 029 C2 and DE 199 51 921 C2, where different arrangements at a switchgear cabinet are illustrated.